The participants form groups of three. One is the engineer and the other two are the robots. The robots stand back-to-back. When the engineer touches their heads, they start to move but only go forward. Even if they hit an obstacle they can’t turn. The engineer’s goal is to bring the two robots face to face. S/he can make them turn right at a ninety-degree angle by touching them on their right shoulder and similarly turn left at a ninety-degree angle by touching them on their left shoulder.